The invention relates to an electric motor with a damping device incorporating a disc-shaped damping mass, consisting at least partly of a magnetisable material, which is axially movable and freely rotatable in relation to the driven element; and more particularly to a synchronous motor in which the mass is pressed as a result of a magnetic force against a friction plate rotating with the driven element.
An electric motor of this kind with a damping device, which is used in a known fashion to improve the starting behavior or to stabilise the running of a motor is known from U.S. Pat. No. 3,790,831, the magnetic force which presses the damping mass against a friction plate rotating with the driven gearwheel is provided by a permanent magnet incorporated in the damping mass. Providing a permanent magnet of this kind is, however, relatively expensive. A method is also known, for example from U.S. Pat. No. 3,197,659, for pressing the damping mass against a friction plate rotating with the driven element by means of an incorporated spring, but this also involves additional cost in connection with the assembly of the device as a whole.